2.1.3 Atomic Masses

2.1.3 Atomic Masses

1. Relative Atomic Mass

   • used for giant compounds
   • i.e. CaBr2 = 40.1 + (79.9x2) = 199.9

2. Relative Isotopic Mass

   • Mass of an atom of an isotope compared with 1/12 of the mass of carbon-12

3. Relative Atomic Mass

   • weighted mean mass of an atom of an element compared to 1/12 mass of carbon-12
   • weighted mean mass because it takes into account all the isotopes

4. Relative Molecular Mass

   • used for simple molecules
   • i.e. Mr(Cl2) = 35.5 x 2 = 71